Faculty Research Publications (Rangeland Ecology and Management)http://hdl.handle.net/1957/29210
Tue, 03 Mar 2015 23:02:59 GMT2015-03-03T23:02:59ZCan Imazapic and Seeding Be Applied Simultaneously to Rehabilitate Medusahead-Invaded Rangeland? Single vs. Multiple Entryhttp://hdl.handle.net/1957/54801
Can Imazapic and Seeding Be Applied Simultaneously to Rehabilitate Medusahead-Invaded Rangeland? Single vs. Multiple Entry
Davies, K. W.; Madsen, M. D.; Nafus, A. M.; Boyd, C. S.; Johnson, D. D.
It has recently been proposed that the cost of rehabilitating medusahead (Taeniatherum caput-medusae [L.] Nevski)-invaded
rangelands may be reduced by concurrently seeding desired vegetation and applying the preemergent herbicide imazapic.
However, the efficacy of this ‘‘single-entry’’ approach has been inconsistent, and it has not been compared to the multiple-entry
approach where seeding is delayed 1 yr to decrease herbicide damage to nontarget seeded species. We evaluated single- and
multiple-entry approaches in medusahead-invaded rangelands in southeastern Oregon with seeding for both approaches
occurring in October 2011. Before seeding and applying herbicide, all plots were burned to improve medusahead control with
imazapic and prepare the seedbed for drill seeding–introduced perennial bunchgrasses. Both approaches effectively controlled
medusahead during the 2 yr postseeding. However, almost no seeded bunchgrasses established with the single-entry treatment
(< 0.5 individals • m⁻²), probably as a result of nontarget herbicide mortality. Perennial grass cover and density in the single-entry
treatment did not differ from the untreated control. In contrast, the multiple-entry treatment had on average 6.5 seeded
bunchgrasses • m⁻² in the second year postseeding. Perennial grass (seeded and nonseed species) cover was eight times greater in
the multiple-entry compared to the single-entry treatment by the second year postseeding. These results suggest that the
multiple-entry approach has altered the community from annual-dominated to perennial grass-dominated, but the single-entry
approach will likely be reinvaded and dominated medusahead without additional treatments because of a lack of perennial
vegetation.
To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the Society for Range Management and can be found at: http://www.bioone.org/loi/rama.
Sat, 01 Nov 2014 00:00:00 GMThttp://hdl.handle.net/1957/548012014-11-01T00:00:00ZMedusahead Invasion Along Unimproved Roads, Animal Trails, and Random Transectshttp://hdl.handle.net/1957/51674
Medusahead Invasion Along Unimproved Roads, Animal Trails, and Random Transects
Davies, Kirk W.; Nafus, Aleta M.; Madsen, Matthew D.
Medusahead (Taeniatherum caput-medusae [L.] Nevski), an exotic annual grass, is rapidly spreading and
causing ecological damage across the western United States. Because this exotic plant occupies vast areas and because
management resources are limited, it is critical that land managers prioritize where they direct treatment and monitoring
efforts. Identifying where and by what means medusahead is spreading could provide valuable information to assist
in determining where prevention and control efforts should be applied. We compared medusahead invasion levels along
unimproved roads, animal trails, and random transects at 6 sites in southeastern Oregon to determine where medusahead
was more common and to identify potential vectors for its spread. Medusahead was more common and its cover
was greater along unimproved roads than along trails and random transects. Medusahead infestations were also larger
along roads. Medusahead was more common along animal trails than along random transects, but differences were less
evident. Our results suggest that medusahead spreads along roads. This outcome implies, though not conclusively, that
vehicles may be one of the most important vectors for medusahead spread. Our results also suggest that animals may be
a vector for medusahead dispersal; however, invasions were much more concentrated near roads than trails, suggesting
that medusahead management along roads should receive higher priority. Medusahead invasion is not random across
the landscape, and thus, control and monitoring efforts can be prioritized, based on potential vector pathways, to manage
this invasive plant.
To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the Monte L. Bean Life Science Museum, Brigham Young University and can be found at: http://www.bioone.org/loi/wnan.
Wed, 01 May 2013 00:00:00 GMThttp://hdl.handle.net/1957/516742013-05-01T00:00:00ZLarge-Scale Downy Brome Treatments Alter Plant-Soil Relationships and Promote Perennial Grasses in Salt Desert Shrublandshttp://hdl.handle.net/1957/49738
Large-Scale Downy Brome Treatments Alter Plant-Soil Relationships and Promote Perennial Grasses in Salt Desert Shrublands
Schantz, Merilynn C.; Monaco, Thomas A.; Call, Christopher A.; Sheley, R. L.
Because invasive annual grasses can strongly influence soil resource availability and disturbance regimes to favor their own
persistence, there is a great need to understand the interrelationships among invasive plant abundance, resource availability, and
desirable species prominence. These interrelationships were studied in two salt desert sites where the local abundance of downy
brome (Bromus tectorum L.) varied spatially and increased more than 12-fold over a 3-yr period. We measured downy brome
percentage cover, resource availability, and soil chemical and physical properties within 112 plots per site and found significant
negative associations between downy brome abundance and both soil water content (P < 0.05; r = -0.27 to -0.49) and nitrate
accumulation (P < 0.05; r = -0.34 to -0.45), which corroborated with the direction and strength of multivariate factor loadings
assessed with principal component analysis. We then applied factorial combinations of prescribed burning and preemergence
herbicide at management-relevant scales (i.e., 6 to 46 ha) as well as biomass removal to smaller plots (12.25 m²) at both sites to
determine their impact on downy brome, soil resources, and resident plant species. Burning and herbicide applications,
especially when combined, significantly reduced downy brome cover (P = 0.069 to 0.015), which in turn increased soil nitrate
accumulation and water content in the spring. Furthermore, for one shrubland site that was seeded 6 yr previously, the
combination of burning and herbicide treatments significantly increased perennial grass percentage cover in the 2 yr
posttreatment (P < 0.05). Results not only demonstrate the strong relationships between downy brome abundance, soil
resources, and residence species for impoverished salt desert shrub ecosystems, but also suggest that restoration and
management efforts must include tactics that facilitate resource use by the residual plant community or establish a greater
abundance of species capable of high resource acquisition in the spring.
To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the Society for Range Management and can be found at: http://www.srmjournals.org/loi/rama.
Thu, 01 May 2014 00:00:00 GMThttp://hdl.handle.net/1957/497382014-05-01T00:00:00ZIs fire exclusion in mountain big sagebrush communities prudent? Soil nutrient, plant diversity and arthropod response to burninghttp://hdl.handle.net/1957/49731
Is fire exclusion in mountain big sagebrush communities prudent? Soil nutrient, plant diversity and arthropod response to burning
Davies, Kirk W.; Bates, Jonathan D.; Boyd, Chad S.; Nafus, Aleta M.
Fire has largely been excluded from many mountain big sagebrush communities. Managers are reluctant to
reintroduce fire, especially in communities without significant conifer encroachment, because of the decline in sagebrush-associated
wildlife. Given this management direction, a better understanding of fire exclusion and burning effects is
needed. We compared burned to unburned plots at six sites in Oregon. Soil nutrient availability generally increased with
burning. Plant diversity increased with burning in the first post-burn year, but decreased by the third post-burn year.
Burning altered the arthropod community, which included doubling the density of arthropods in the first post-burn year.
Some arthropod Orders increased and others decreased with burning. For example, Araneae were 1.7- and 1.8-fold less and
Hemiptera were 6.6- and 2.1-fold greater in the burn compared with the control in 2008 and 2009. Our results provide
evidence that burning can create spatial and temporal heterogeneity in sagebrush communities and thus, it is an important
component of the ecosystem. We suggest that management plans for many mountain big sagebrush communities may need
to include infrequent burning. At the very least managers should be aware that fire exclusion has some potentially negative
effects other than the encroachment of conifers in these communities.
To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the International Association of Wildland Fire and published by CSIRO Publishing. It can be found at: http://www.publish.csiro.au/nid/114.htm.
Thu, 03 Apr 2014 00:00:00 GMThttp://hdl.handle.net/1957/497312014-04-03T00:00:00Z